remove duplicated code and rework algorithms to end up with smaller code

diff --git a/coreutils/comm.c b/coreutils/comm.c
index b0384fe8798660524594689967cab0aea0155584..7471c3b318ff6e3a2919aee5ff46639ff51d526a 100644 (file)
--- a/coreutils/comm.c
+++ b/coreutils/comm.c
@@ -40,15 +40,16 @@ static int both;
 /* writeline outputs the input given, appropriately aligned according to class */
 static void writeline(char *line, int class)
 {
-       if (class == 1 && !only_file_1)
+       if (class == 0) {
+               if (!only_file_1)
                return;
-       else if (class == 2) {
+       } else if (class == 1) {
                if (!only_file_2)
                        return;
                if (only_file_1)
                        putchar('\t');
        }
-       else if (class == 3) {
+       else /*if (class == 2)*/ {
                if (!both)
                        return;
                if (only_file_1)
@@ -60,73 +61,69 @@ static void writeline(char *line, int class)
 }
 
 /* This is the real core of the program - lines are compared here */
-static int cmp_files(char **infiles)
+static void cmp_files(char **infiles)
 {
-       char thisline[2][100];
+#define LINE_LEN 100
+#define BB_EOF_0 0x1
+#define BB_EOF_1 0x2
+       char thisline[2][LINE_LEN];
        FILE *streams[2];
-       int i = 0;
+       int i;
 
-       for (i = 0; i < 2; i++) {
-               streams[i] = (strcmp(infiles[i], "=") == 0 ? stdin : bb_xfopen(infiles[i], "r"));
-               fgets(thisline[i], 100, streams[i]);
+       for (i = 0; i < 2; ++i) {
+               streams[i] = ((infiles[i][0] == '=' && infiles[1][1]) ? stdin : bb_xfopen(infiles[i], "r"));
+               fgets(thisline[i], LINE_LEN, streams[i]);
        }
 
        while (thisline[0] || thisline[1]) {
                int order = 0;
-               int tl0_len = strlen(thisline[0]);
-               int tl1_len = strlen(thisline[1]);
+
+               i = 0;
+               if (feof(streams[0])) i |= BB_EOF_0;
+               if (feof(streams[1])) i |= BB_EOF_1;
 
                if (!thisline[0])
                        order = 1;
                else if (!thisline[1])
                        order = -1;
                else {
+                       int tl0_len, tl1_len;
+                       tl0_len = strlen(thisline[0]);
+                       tl1_len = strlen(thisline[1]);
                        order = memcmp(thisline[0], thisline[1], tl0_len < tl1_len ? tl0_len : tl1_len);
                        if (!order)
                                order = tl0_len < tl1_len ? -1 : tl0_len != tl1_len;
                }
 
-               if ((order == 0) && (!feof(streams[0])) && (!feof(streams[1])))
-                       writeline(thisline[1], 3);
-               else if ((order > 0) && (!feof(streams[1])))
+               if (order == 0 && !i)
                        writeline(thisline[1], 2);
-               else if ((order < 0) && (!feof(streams[0])))
-                       writeline(thisline[0], 1);
-
-               if (feof(streams[0]) && feof(streams[1])) {
-                       fclose(streams[0]);
-                       fclose(streams[1]);
-                       break;
+               else if (order > 0 && !(i & BB_EOF_1))
+                       writeline(thisline[1], 1);
+               else if (order < 0 && !(i & BB_EOF_0))
+                       writeline(thisline[0], 0);
 
-               } else if (feof(streams[0])) {
-                       while (!feof(streams[1])) {
-                               if (order < 0)
-                                       writeline(thisline[1], 2);
-                               fgets(thisline[1], 100, streams[1]);
-                       }
-                       fclose(streams[0]);
-                       fclose(streams[1]);
+               if (i & BB_EOF_0 & BB_EOF_1) {
                        break;
 
-               } else if (feof(streams[1])) {
-                       while (!feof(streams[0])) {
-                               if (order > 0)
-                                       writeline(thisline[0], 1);
-                               fgets(thisline[0], 100, streams[0]);
+               } else if (i) {
+                       i = (i & BB_EOF_0 ? 1 : 0);
+                       while (!feof(streams[i])) {
+                               if ((order < 0 && i) || (order > 0 && !i))
+                                       writeline(thisline[i], i);
+                               fgets(thisline[i], LINE_LEN, streams[i]);
                        }
-                       fclose(streams[0]);
-                       fclose(streams[1]);
                        break;
 
                } else {
                        if (order >= 0)
-                               fgets(thisline[1], 100, streams[1]);
+                               fgets(thisline[1], LINE_LEN, streams[1]);
                        if (order <= 0)
-                               fgets(thisline[0], 100, streams[0]);
+                               fgets(thisline[0], LINE_LEN, streams[0]);
                }
        }
 
-       return 0;
+       fclose(streams[0]);
+       fclose(streams[1]);
 }
 
 int comm_main(int argc, char **argv)
@@ -142,5 +139,6 @@ int comm_main(int argc, char **argv)
        only_file_2 = !(flags & COMM_OPT_2);
        both = !(flags & COMM_OPT_3);
 
-       exit(cmp_files(argv + optind) == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+       cmp_files(argv + optind);
+       exit(EXIT_SUCCESS);
 }